The sun’s absolute magnitude is described as in comparison to other stars.
a. very large
c. very small
b. average
d. absent

The sun’s absolute magnitude is described as (B) average in comparison to other stars. Apparently, giving the exact value of sun's absolute magnitude, that is -26.74. Absolute magnitude measures the intrinsic brightness of a star, of a celestial object in itself.

Answer (d) may increase or decrease porosity through dissolution or deposition;